Aqueous vehicle for plant spraying materials



A y 0 wake June 20, 1939. J. R. ALLISON- 2,162,905

AQUEOUS VEHICLE FOfi PLANT smmme MATERIALS Filed July 10, 1956 2 Sheets-Sheet 1 ALBUMlN-RESINATE RATIO THICKNESS ALBUM! H -RES INATE RA'I ID lOO-O O-IOO FIG. 3

M MICHAEL VISCOSITY I50 JOHN R. ALLISON VENTOR June 20, 1939. J. R. ALLISON 2,162,905

AQUEOUS VEHICLE FOR PLANT S PRAYING MATERIALS Filed July 10, 1936 2 Sheets-Sheet 2 IOO-O w-lO KJ-ZO 703) ALBUM IN- RESINATE RATIO 33-1) 20-80 O-IOO FIG. 4 SURFACE TENSIONS FIG. 5 SURFACE TENSION RELATIONS JOHN R.ALLISON IIYVENTOR ATTORNEY Patented June 20,1939

AQUEOUS VEHICLE FOR PLANT SPRAYING MATERIALS John R. Allison, Whittier, Calif.

Application July 10, 1936, Serial No. 89,979

8 Claims.

The primary object of this invention is to provide an aqueous vehicle by means of which any preferred insecticide, fungicide, germicide or other protective agent may be applied to any kind of vegetation.

This application is a continuation in part of my earlier co-pending application, Serial No. 759,069 filed December 24, 1934.

The specific object 'of this invention is to provide a vehicle of the class described which is compatible with most of the protective agents commonly used, which maybe applied to both fruit and foliage of fruit trees in a film or layer of even and controllable thickness, which may be prepared and used economically and which may readily be removed from the ripe fruit by washing with water or dilute aqueous alkalis.

As is well known, most of the protective agents are applied to fruit trees in solution, dispersion or suspension in a vehicle consisting mainly of water. For example, an agent such as nicotine would normally be entirely in solution; emulsified petroleum oils are dispersed in the vehicle, while solid agents such as lead arsenate are largely or entirely in suspension.

The vehicle, containing the agent or agents in one or more of the above conditions, is reduced by mechanical means to the form of a fine spray or mist which is directed against the leaf and fruit surfaces to be protected and on which it forms a relatively thin liquid film. This film, on the removal of the water by evaporation, leaves a more or less permanent coating consisting of the agent proper together with any nonvolatile substances comprised in the vehicle, this coating being, so far as possible, retained on the protected surfaces until or unless it is intentionally removed.

A satisfactory aqueous vehicle for the described purpose must have all of the following characteristics:

l) Compatibility-(a) It must be readily miscible with the agent which it is intended to convey and must not react with that agent to depreciate the valuable properties of either the agent or the vehicle. (13) It must be capable of any desired degree of dilution with such alkaline, hard or salty waters as may be locally available without depreciation of any of the valuable properties of the vehicle.

(2) Spreading property-It must have its surface tension so controlled that the minute drops of which the spray or mist is composed may, on contact with the surface to be protected, immediately spread over that surface to form a continuous film of uniform thickness throughout.

(3) Supporting property.-The liquid film initially formed on the protected surface should have or should rapidly acquire the highest viscosity consistent with the proper development of the spreading property. This is requisite in order to 5 avoid dripping or skidding" (the bodily movement of the film to the lower portion of the leaf or fruit by which serious wastage may be incurred). It also restrains the tendency towardpulling or beading (the tendency of the film 10 to gather into drops or thickened areas during the time required for the drying and ultimate fixation of the film, such concentration usually producing the burning or spotting of the protected surface).

(4) Adhesive property.--The permanent film 15 ultimately produced by drying of the initial liquid film on the surface to be protected should be tough,-coherent and strongly adherent to the surface; so that it may not become detached by the action of the wind or other atmospheric effects.

, (5) Emulsifying property-Liquids such as petroleum products, which are insoluble in water, are applied in the dispersed form after emulsification with the vehicle. Petroleum oils as such, or with the addition of certain substances which 25 alter their surface tensions, must become emulsified on proper admixture with the vehicle, and where such oils are the intended agents the property of producing and maintaining the emulsified state is of prime importance. If, however, the 30 oleaginous agent has previously been treated in such manner as to make it water-miscible (e. g. the so-called soluble oils) or if the agent is of other than oleaginous character, the emulsifying property is of no importance.

(6) RemovabiZity.-The ultimate film must be of such nature as to readily be removed from the ripe fruit by washing, this removal being requisite to bringing the fruit to salable appearance and to freeing it from all traces of poisonous or other 40 objectionable matter.

It should be noted that one of these characteristics is to some degree antagonistic to others.

It appears to be impossible to develop the spreadlng characteristic (2) to the greatest possible extent without limiting the development of the supporting, adhesive and emulsifying properties (3 i--5), while on the other hand the development of any one of the last named characteristics usually accentuates the other characterso istics in the same group.

For this reason it is requisite,'for the application of all the various types of protective agents, to provide two aqueous vehicles: first, one in which the spreading'property is developed 56 to the fullest extent and is under complete control, this being suited to the application of water soluble agents and of such powdered solids as have little tendency to separate or agglomerate; second, one in which the emulsifying property and, with it, the supporting and adhesive characteristics, are sumciently developed to make it suited to the application of oils or of powders which tend to segregation from the vehicle.

The present invention is of a vehicle .of the first type, in which the spreading property is developed to an extent not heretofore attained and is under a control not heretofore exercised. An application covering a vehicle of the second type is filed simultaneously herewith, under the title Aqueous vehicle having emulsifying properties and bearing Serial No. 89,980.

The vehicle of the instant invention is composed of well known materials, to-wit: potassium resinate and albumin, with optionally a small proportion of ammonia and with sufficient water to bring the materials into solution. Both potassium resinate and albumin have heretofore been used in aqueous spray vehicles but, so far asI am aware, they have not been used in combination. The novelty as well as the value of the invention lies in the combination itself and leaves and ripe fruit. really perfect spread was had only in the narin the control of the properties of the combination which is afiorded by varying the relative proportions of these constituents.

In order to show the variation in properties of the combination with variations in the propprtions of the constituents, the following experiment was conducted.

Various mixtures of albumin with potassium resinate were made in which the relation albuminzresinate was varied by 10% steps from 90: 10 to 10:90. All of these mixtures contained the same proportion of water, such as to bring the total solids to 662 grams per gallon. of albumin alone and potassium resinate alone were also prepared in the same degree of concentration.

Each of these solutions was then diluted with water in the same proportion, approximately 2400 parts water to 1 part solution, and applied to orange trees by spraying in the usual manner. Care was taken to apply substantially the same quantity in each case.

Observations were then made of the completeness of the spread on old leaf, on new green leaf, and on fruit, these spreads being graded by a skilled operator from no spread to complete spread in five steps. Observations were also made of the thickness of the average film in V the wet state, these observations being recorded as thin, medium, and thick. r

These observations are recorded in'diagrammatic form in the attaching drawings, in which Fig. 1 exhibits the completeness of the spread and Fig. 2 the thickness of the film. It will be understood that these curves have no numerical value and are merely the record of the judgment of a person skilled in the art of spraying, but as such they are believed to be sufflciently accurate to serve as the basis for certain general conclusions.

First, as regards the spreading property: a complete spread is much more difiicult to attain on the young green leaves than on the older On the young leaves a row range between and 40% albumin, but a fgood spread, satisfactory in most cases, was obtained within the range from 80% to 30% a1- Solutions bumin, this same range giving a perfect spread on old leaves and fruit. So far as the spreading property is concerned, the commercially useful range appears to lie between 80% and 30% albumin while during certain seasons it might be desirable to remain within the range to 40% albumin in order to protect the young leaf.

Second, the film thickness increases between 100% and albumin and again decreases between 60% and 0% albumin. It cannot be said in general terms that either a thin or a thick film is intrinsically desirable, this depending on the character of the protective agent and the quantity which it is desired to apply to the protected surface. However, it should be noted that the thin film obtained with albumin alone is due to dripping and that it may be corrected by decreasing the dilution of the spray compound (i. e., by using more of it) while the thin film obtained with compounds high in resinate is due to skidding of the film, which is aggravated by increasing the dosage.

The property of adhesiveness increases progressively as the proportion of resinate is increased. Under ordinary conditions of use the compound containing 20% resinate is sufliciently adhesive and one containing 40% has this property highly developed.

The properties of compatibility and of removability are fully developed in both of the constituents and in all proportionate combinations.

From the commercial standpoint the keeping properties of these compounds is a matter of serious importance, as they are often manufactured a long time before they are used. This property is entirely absent in albumin alone and is fully developed in the resinate. The addition of ammonia materially aids in preventing the fermentation and decay by albumen, but even with the addition of 2 by volume of aqueous ammonia to the above compounds the albumin alone and the compound containing albumin decayed after two weeks standing at room temperature while the 80% albumin compound showed signs of fermentation. Compounds containing 70% or less of albumin are almost indefinitely permanent.

The curves presented in Figs. 3 to 5, inclusive, are presented as showing the remarkable departure from straight line averages of two accurately measurable propertiesviscosity and surface tension-when these measurements are made on the graduated series of mixtures above described.

Fig. 3 is a graph of the MacMichael viscosities of the eleven test samples, starting with albumin and graduating by 10% steps to 100% resinate, concentration 662 grams per gallon, #30 torsion wire used.

Fig. 4 records the surface tensions, in dynes per square centimetre, of the eleven test samples, first in the above named concentration, then further diluted with 800 and with 1600 parts additional water. These determinations were made with the du Nuoy surface tension apparatus which gives a reading for water distilled from glass of approximately 70 dynes.

Fig. 5 records, for the samples as above diluted, the increase in surface tension due to dilution, i. e., the difference between the surface tension of the diluted sample and the surface tension of the corresponding undiluted sample.

Referring first to Fig. 3, the enormous increase in viscosity with a relatively small proportion of resinate will be noted. The peak of this curve,

which is beyond the capacity of the particular instrument used, lies somewhere between 80% and 60% albumin, the highest actual reading being on the 70% sample. This sample showed approximately sixty times the viscosity of 100% albumin solution of the same concentration and over one hundred and twenty times the viscosity of the corresponding resinate solution.

As this increase in viscosity is not accompanied by any reduction in solubility nor by any indications of precipitation or gelatinization, it is my belief that this particular proportion of albumin to resinate (approximately 70:30) is one at which a chemical rearrangement takes place, probably with buminate and albumin resinate (the amphoteric character of albumin is well known). Chemical theorizing aside, and recognizing that the viscosity of the concentrated product is immaterial from the practical standpoint, the wide departure of the viscosity curve from the straight line (the fine broken line of the figure) which would result from the mixture of twomutually soluble and mutually indifferent bodies appears to negate any possibility that this compound is a mere mixture in which the two constituents display each its own characteristics.

It is also noted that the viscosity points for 90:10, 20:80, and 10:90 albumin resinate ratio fall almost exactly on the average line, and the very decided breaks in the surface tension curves at these points (see Fig. 4) may also indicate that" outside these limits chemical rearrangement does not take place.

The curves of Fig. 4, and particularly those showing the surface tensions of the diluted samples, are directly relevant to the spreading property of the spray as used. Spreading power is the composite of two counteracting forces-the attraction or wettability of the surface of the leaf for the liquid, which tends to indefinitely spread the liquid, and the surface tension of the liquid which tends in the opposite direction, to draw the liquid away from the leaf surface into beads or drops.

Wettability is not accurately measurable and there is no standardized test surface which may be substituted for the leaf surface and no two leaves are identical in this regard. Practically all that we know about Wettability is that old leaves are more readily wettable than new, and that the Wettability with albumin solutions somewhat exceeds that with resinate solutions. This difference probably accounts for the fact that the optimum albumin resinate ratio, that which actually gives the best spread, is somewhat greater than that which would be indicated by the surface tension curves.

Assuming Wettability to be constant in any given case, surface tension then becomes a direct measurement of spreading power, which increases as the surface tension of the diluted liquid It is therefore highli noteworthy a 10:90 albumin resinate ratio is tension curve, as deterdiminishes. that until reached the surface -mined by repeated observations, lies far below the straight line representing the average surface tension of the two constituents in various proportions, even an albumin solution producing a very sharp reduction in the surface tension of the diluted liquid. It will also be noted that the lowest surface tensions occur within the range 60:40 to 30:70 in the 1:800 dilution and in a still narrower range, 50:50 to :60 in the case of the 1:1600 dilution.

the formation of potassium alat 10% addition of resinate to In practice the most desirable working range, as

determined by experience, is from 70530 to 60:40

albumin resinate ratio.

As will be seen from the graphs in Fig. 4; f

surface tension is in all cases increased by dilution and the permissible range of proportion for any given surface tension narrows as jdilution is increased. Thus for a surface tension of dynes the available range is only from :50 to 40:60 in' the 1:1600 dilution while in the 1:800 dilution the possible range is from 85:15fto 20:80. Economy is therefore enhanced by working in the narrower ranges which permit the higher degrees of dilution. I

It will be evident from the above figures (and has been amply demonstrated in the application of large quantities of my compounds in actual spraying practice) that useful spray vehicles may be prepared by combining albumin with potassium resinate in proportions ranging from 80% albumin: 20% resinate to 30% albumin: 70% resinate. Above 90% albumin the spread is unsatisfactory and the dripping tendency is objectionable, above 80% the lack of keeping properties make the material almost useless. Below 30% albumin the spreading property is too little developed for most uses.

For general commercial use, however, I prefer to work within that range which gives the greatest value to all the desired properties, i. e., within the range 65% albumin: 35% resinate to 50% albumin: 50% resinate. Within these limits the spreading value is at its maximum on all the classes of surface to be protected; heading, dripping, and skidding are entirely avoided; the film thickness can be controlled at will by varying the dilution and the quantity of spray applied; adhesiveness is so developed as to cafe for the most difficult conditions; the compound (with the addition of ammonia) is absolutely permanent and may be stored for any desired time without deterioration; compatible with practically all protective agents (bearing in mind that it has "very slight emulthe compound is Potassium resinate pounds 108 Albumin (preferably blood albumin) pounds 175 Water, sufficient to make gallons 190 This mixture is best prepared by dissolving the albumin in sayllO gallons water, dissolving the resinate in say 55 gallons water, and mixing the two solutions. The albumin and the resinate are of such bulk as to bring the total quantity to about 190 gallons.

If this mixture is not to be used immediately, it may be desirable to add to the above quantity about three gallons of 26 aqua ammonia or a corresponding quantity of other strength. The ammonia is preferably added to the resinate solution before the two solutions are mixed.

The ammonia is added mainly for its well known function as a preservative and therefore is not includedin the formula. It has however been noted that, on standing, the material of the formula plus the ammonia undergoes a very desirable increase in viscosity which is not accompanied by any decrease in spreading properties.

This change is believed to be due to the formation of ammonium albuminate and the addition of the ammonia is recommended for this reason also.

Within narrow limits the materials of the above formula may be substituted by equivalents.

For the alkaline. ingredient in potassium resinate I may substitute ammonium as a full equivalent. In fact, were it not for the difiiculty in preparing the ammonium salt, its substitution would be desirable because of its greater freedom from the deleterious efiects of hard waters. Sodium resinate is a possible substitute for the potassium salt but is of a low order of water solubility and requires excessive dilution.

The acid ingredient in potassium resinate is, commercially, common rosin or colophony. 0bviously other resins and exudates of an acid nature might be substituted, though such substitution would in most cases be barred on the score of excessive cost.

The salts of oleic or other fatty acids cannot be substituted for the resinates in the above formula as the full equivalent. Partial substitution of alkaline oleates produces highly desirable and useful vehicles, but the products of this substitution have different characteristics and a different usefulness. Vehicles containing material proportions of oleates are fully described and claimed in the copending application.

Casein is decidedly not the equivalent of albumin in the above formula. For this there are two reasons, both of material importance.

First, the substitution of casein for albumin in other than a minor proportion makes it impossible to utilize, for dilution, local waters carrying material proportions of alkali earths or metallic salts. It will be understood that the proportion ofwater shown in the formula is not that occurring in the vehicle as actually used, but is such as to produce a concentrate adapted to packaging and shipping. For actual use in spraying this concentrate is further diluted with perhaps 2500 volumes of water which must, of course, be such as is locally available.

Over extensive fruit growing areas the only.

waters obtainable for dilution areheavily charged with lime, magnesia, chlorids, and sulfates, and when these waters are used to dilute mixtures containing caseinates, material proportions of the casein are precipitated and rendered inactive. Further, this precipitation reduces the spreading value which it is the prime purpose of the casein to produce when so substituted, and very hard waters may totally destroy the spreading characteristic. Still further, the precipitates so produced are water-insoluble and of a sticky and adhesive nature, and when deposited on the fruit and dried and oxidized during the ripening period are diflicult or impossible to remove by water washing, thus leaving the washed fruit discolored at the best and poisonous in cases where toxic agents have been used. Albumin'is not thus precipitated by hard waters.

Second, the increased spreading value resulting from the combination of albumin with alkaline resinates is not realized when casein is substituted for the albumin, and the product of the substitution is of decidedly inferior value for the applicants present purpose.

It should, however, be understood that the substitution of a small proportion of the albumin by casein is not fatal to the value of the vehicle. On the contrary, and particularly in vehicles of the described type in which the albumin proportion is at the maximum, a limited substitution of casein for albumin may be advantageous as improving the adhesion characteristic, which may be deficient because of the low adhesive value of albumin. This substitution, however, should not be carried beyond about one-fifth of the original quantity of albumin.

The properties of the albumin-resinate compound above described may in some cases be materially improved, particularly as to stability in storage and as to compartibllity with hardwaters, by the addition of a small amount of a mild alkali, suflicient to bringit to a distinctly alkaline reaction. For this purpose I prefer to use sodium silicate, sodium hexametaphosphate or sodium carbonate, or the corresponding salts of potassium.

I claim:

1. A vehicle for plant spraying materials comprising albumin and an alkali resinate in aqueous solution.

2. A vehicle for plant spraying materials comprising albumin and an alkali resinate in proportions by dry weight ranging from 78% albumin +22% resinate to 27% albumin +73% resinate.

3. A vehicle for plant spraying materials comprising albumin and an alkali resinate in proportions ranging from 70% albumin +30% resinate to 50% albumin +50% resinate.

4. A vehicle for plant spraying materials consisting substantially of albumin and an alkali resinate, together with casein in quantity not greater than one-fourth that of the albumen.

5. A vehicle for plant spraying materials: albumin, an alkali resinate and an excess of a mild alkali.

6.A vehicle for plant spraying materials: an aqueous solution of albumin, an alkali resinate and an excess of ammonia.

7. A vehicle for plant spraying materials comprising albumin and a resinate selected from the group consistingof potassium resinate and ammonium resinate.

- 8. A vehicle for plant spraying materials comprising a mixture of albumin and an alkali resinate.

JOHN R. ALLISON. 

